RESPONSE TO SELECTION AND REALIZED HERITABILITY FOR EARLY GROWTH IN THE SECOND-GENERATION BREEDED LINE OF TURBOT (SCOPHTHALMUS MAXIMUS L.)
大菱鲆（Scophthalmus maximus）家系选育F2早期选择反应和现实遗传力估计

The second-generation selected line of turbot was constructed by a consecutive selection for faster growth in the base population. Response to selection for 6 months live weight of turbot (Scophthalmus maximus L.) were estimated by three methods:Ⅰ. Comparing the least squares means of the second-generation selected line and control line,Ⅱ. Comparing the estimated breeding values for live weight between the first- and the second-generation selected line, and Ⅲ. Comparing the estimated breeding values of the second-generation selected line and control line, respectively. Based on selection response values evaluated, realized heritability and genetic gain were also estimated. The results showed that response to selection, realized heritability and genetic gain estimated by three methods were different and their mean values were 3.1983±0.5880, 0.2941±0.0531 and 8.70±1.60, respectively, which revealed that large enough early selection response, moderate realized heritability and lower genetic gain were obtained. It was concluded that the family selection was an effective approach to improving growth traits of turbot, at the same time, the population still has additive genetic variance to enable further improvement.